Blame it on your brain

Dr Kyle Trieber, University of Cambridge

Our improved insight into the brain has been used in a couple of cases to argue that the defendant is not to blame for their actions: the defence argued that it was a disease, or tumour, inside of the their brain which caused them to commit crimes. But should this be the future of our courtrooms? Connie Orbach spoke to Dr Kyle Trieber, lecturer in neurocriminiology from the University of Cambridge to find out...

Kyle - It’s becoming more common to see neuroscientific evidence used in the courts. In the UK, there’s a lot more restriction on it’s use at the moment. In other countries that we see, there’s evidence being used on a much more regular basis. There isn’t a very clear protocol for how to use this material and that’s something that law is dealing with at the moment. But, I come from the neuroscience side, and one thing that I see when I am crossing over into the legal area is that there’s a very different kind of language being spoken. So, neuroscientist are speaking a scientific language, we’re looking to find out what the truth is and we want to understand what is actually the processes that are underlying a particular behaviour. When you’re looking at the legal side of it, you’re trying to have two sides of the story, specify whether or not this person is responsible for the action or whether they should be held responsible, and it’s a very different kind of approach. I think there’s going to be a discussion that’s going to have to be had between the sciences and the law side to better understand how we’re going to integrate these two bodies of knowledge, which both have a great deal to bring to the table but to actually move forward for how we can use this information and how we can make it accessible to a court.

Connie - If someone were to say to me - “oh, there is a difference in their brain structure.” It’s very easy to go - “okay, well that sounds like a good excuse.”

Kyle - Yes, there’s a lot of interesting research about the fact that if you show someone an image of the brain and they have damage to the brain, then that is very influential on how they think about that person, and that person's capabilities, and that person’s responsibility for the criminal action, and the role that that damage would play.

Connie - So, clearly neural evidence or blaming it on the brain is a powerful defence but, maybe, the way it is used in court as ‘evidence’ for or against criminal behaviour, is pretty far from the more nuaunced information that a scientist sees. So, is there ever a circumstance where Kyle would be happy to say, there that abnormality is the reason for the crime?

Kyle - When you have these very extreme case, very colourful cases where, for example, you have a very rare kind of tumour situation - it’s a very extreme kind of case. Most offending behaviour that we have there seems to be no real link to any kind of specific disability or specific brain damage or injury of any sort. So, it is a direction that we certainly need to be aware of because individuals will have certain vulnerabilities. But one things I always stop to think about in these kind of cases is, if there was an individual who has exactly these same cognitive abilities, are there individuals like that who aren’t offending, who aren’t committing crime? And, in the vast majority of cases we can find examples where that is the case, and that suggest to us that this is not the cause of their offending. That’s not to say that it isn’t playing a role in their offending, but it also isn’t determining that offending. It doesn’t make make it absolutely that offending is absolutely going to happen.

One of the things that a neuroscientist would like to communicate to people is that we’re still learning a lot. We don’t actually have a very good range of knowledge as to what is normal. So, what are the variations we see in brains? Normally people’s brain structures will vary, people’s brain functioning will vary. To what extent does that actually lead them to behave in different ways? I don’t think, at the moment, we have enough of an understanding of that to be clear to say, “if you have this particular brain structure or this functional abnormality, this is the result you’re going to get as far as behaviour.”

Connie - Similar to genetics in the nature/nurture debate, the brain is just part of the bigger picture, and two people may have the same defect but one will not offend.

Kyle - This is one of the things we really emphasise a lot is the difference between the content and the machinery. So, you have the neurocognitive machinery and this will be based on both the brain and how it developed, and how it functions, but there’s also experiential, so that depends on what your experiences have been on top. Over time, we know that people’s experiences actually influence the structure of the brain as they’re developing.

So, there’s the machinery aspect of it and that will have an impact on how people perceive their environment, how they interact to them, the emotions that they experience but, there’s also the content element. The content is what they learn and what they gather from their environments and, in some ways, there’s evidence, I would think, that suggests that that content may be more important than the machinery. Of course, the content is where we’re going to have the most ability to influence individuals because we can change that information that they’re receiving.

Connie - The content is clearly important, and in Kyle’s own research she’s finding out just how important by following teenagers over years of their lives and studying all of their interactions, and the places they go to see who offends and who doesn’t.

But I’m still interested by these big tumours. The colourful one’s as I’ll put it. Because surely, how much we can blame these is only down to whether or not we can see them. A few decades ago, cognitive impairment wasn’t a defence because we didn’t know someone was impaired. As our technology continues to improve and we can see every little deviation from the norm, is is not possible that the brain as a defence becomes, if anything, more available?

Kyle - This is the exciting bit of neuroscience and neurotechnology at the moment. It is expanding very rapidly. It’s not only becoming more affordable but also there are many new technologies. So, one of the new things that has come out more recently is looking at the connections between areas of the brain and how messages and signals are sent between areas of the brain. We couldn’t see that before and that, actually, is proving to be very important for understanding functioning, being connected to types of functioning that are often mentioned in criminological literature like “psychopathy,” and other kinds of social behaviour because we can now see that that functionality, and we can see the structures that are there because of new types of imaging that we have.

It’s a whole new area that we can look at for understanding the brain and how it works, and the fact that it is very interconnected. It may not be about having this structure or that structure that’s functioning independently, but how they function codependently. And that technology, we would presume, is going to continue to get better and then we will better understand the structure and the function of the brain. But, the more we learn about the functionality of the brain, the more we understand and find that it is very much about interactions, and that we have evolved to interact with our environments and so we are looking for content. We need the content for the brain to develop; we need the content for the brain to function. This is very new field in criminology because criminology has tended to look at the individual or at the environment and now we’re trying to integrate the two. And it’s about the person when they’re in the environment and the action that then results.

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